One of the most important and interesting science fiction novels from the second half of the 20th century. Forms the basis for the current Amazon TV series.
About the book (from wikipedia):
The Man in the High Castle (1963) is an alternative history novel by American writer Philip K. Dick. Set in 1962, fifteen years after an alternative ending to World War II, the novel concerns intrigues between the victorious Axis Powers—Imperial Japan and National Socialist Germany as they rule over the former United States, as well as daily life under the resulting totalitarian rule. The Man in the High Castle won the Hugo Award for Best Novel in 1963.
Reported inspirations include Ward Moore’s alternative Civil War history, Bring the Jubilee (1953), various classic World War II histories, and the I Ching (referred to in the novel). The novel features a “novel within the novel” comprising an alternate history within this alternate history wherein the Allies defeat the Axis (though in a manner distinct from the actual historical outcome).